3-(Difluoromethyl)-2-nitro-5-(trifluoromethyl)pyridine-6-carboxylic acid
3-(Difluoromethyl)-2-nitro-4-(trifluoromethyl)pyridine-6-carboxylic acid
6-(Difluoromethyl)-2-nitro-3-(trifluoromethyl)pyridine-4-carboxylic acid
6-(Difluoromethyl)-2-nitro-4-(trifluoromethyl)pyridine-3-carboxylic acid